Journal of Geochemical Exploration最新文献

{"title":"Fertility assessment of the Kuh-e-Esfand porphyry Cu intrusion in SE Iran: Evidences from silicate chemistry","authors":"Alireza Zarasvandi ,&nbsp;Afsaneh Soltani ,&nbsp;Nader Taghipour ,&nbsp;Mohsen Rezaei ,&nbsp;Johann G. Raith ,&nbsp;Adel Saki ,&nbsp;Ghazal Zarasvandi","doi":"10.1016/j.gexplo.2025.107956","DOIUrl":"10.1016/j.gexplo.2025.107956","url":null,"abstract":"<div><div>The Kuh-e-Esfand porphyry copper prospect, situated 90 km southeast of Jiroft, is associated with Oligocene-Miocene Jebal-e-Barez-type intrusives in the Kerman Cenozoic Magmatic Assambladge (KCMA). In this area, quartz diorite, diorite, and granodiorite porphyry intrusions are emplaced within the Eocene Razak volcanic rocks. Hydrothermal alteration in the study area includes potassic, a deep potassic zone characterized by quartz, sericite, K-feldspar, chlorite ± anhydrite, phyllic, argillic, and propylitic zones. Mineralization, mainly as chalcopyrite and pyrite, occurs predominantly in the transition between potassic and phyllic zones, which extends mostly within the quartz diorite unit.</div><div>On the Al/(Ca + Na + K) vs. An (%) diagram, plagioclase data of quartz diorite units plot along the discriminating line of barren and fertile porphyry Cu intrusions with a more tendency to fertile field (average Al/(Ca + Na + K) = 1.3). Ca- amphiboles in the quartz diorite intrusion are classified as low-Al (Al_T = 0.7–1.6) and high-Al (Al_T = 1.9–2.12) groups. Low-Al amphiboles, characterized by lower water content and higher chlorine concentrations are crystallized at lower temperatures (720.9–0.8 °C), pressures (0.51–0.89 kbar), and under more oxidizing conditions (ΔNNO = 1.47–1.96), compared to high-Al amphiboles, which formed at higher temperatures (866.5–921.7 °C), pressures (1.94–4.02 kbar), and lower oxidation states (ΔNNO = 0.99–1.05). Low-Al amphiboles formed under conditions more favorable for mineralization. Furthermore, re-equilibrated biotites are of Mg-rich, showing high Mg/(Mg + Fe) ratios with low Mn and Al^VI values, which is analogous to those of fertile porphyry Cu intrusions. Geochemical data indicate a hydrous/oxidized calc-alkaline I-type magma that drived from the interaction of mantle-derived magmas with crustal materials in a subduction-related geotectonic setting. The geological, magmatic and geochemical characteristics of the Kuh-e-Esfand prospect are consistent with porphyry Cu mineralization potential.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"282 ","pages":"Article 107956"},"PeriodicalIF":3.3,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"VNIR-SWIR Spectroscopy and Machine Learning: A new approach for Rare Earth Element detection and quantification in fluorapatite veins (Nolans Bore Deposit, Australia)","authors":"Thais Caroline Murer ,&nbsp;Carlos Roberto de Souza Filho","doi":"10.1016/j.gexplo.2025.107955","DOIUrl":"10.1016/j.gexplo.2025.107955","url":null,"abstract":"<div><div>The P-REE-Th Nolans Bore deposit is located in the Northern Territory of Australia and is one of the few known deposits where rare earth elements (REE) are hosted in monomineralic fluorapatite veins. The formation of these REE-fluorapatite veins occurred due to the interaction of carbonatite magma with granulite facies rocks during the peak of metamorphism. In this study, we utilized spectral data from the visible to shortwave infrared (VNIR-SWIR) region, collected at specific points along the drill core, to identify diagnostic parameters of REE host minerals. These data, combined with geochemical analysis, allowed us to estimate the total concentration of rare earth elements (TREE) in the deposit rocks. Our results demonstrated that absorption features indicative of REE could be detected at wavelengths of 580, 744, 804, and 872 nm. Reflectance spectroscopy confirmed the presence of REE in the fluorapatite veins and rocks rich in kaolinite and smectite. Machine learning models were tested to predict TREE concentrations from spectral data. Among the tested models, PLSR and LightGBM achieved comparable overall accuracy, though LightGBM provided more reliable interval predictions. The Multiple-instance learning (MIL) model exhibited higher dispersion, particularly at intermediate TREE values. These findings suggest that reflectance spectroscopy, in conjunction with geochemical data and machine learning algorithms, can be employed to develop models for quantifying REE based on a sample's spectral signature. The predictions made by this model can help determine the spatial distribution of ore content throughout drill cores, reducing reliance on large samples for geochemical testing and decreasing the time required for core analysis.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"282 ","pages":"Article 107955"},"PeriodicalIF":3.3,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145734608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mobilization of trace elements associated with deformation of pyrite from the Xiaoyingpan Au deposit, North China: Implications for fluid evolution and gold mineralization","authors":"Dazhao Wang ,&nbsp;Chaojian Qin ,&nbsp;Shimin Zhen ,&nbsp;Cheng-Biao Leng","doi":"10.1016/j.gexplo.2025.107954","DOIUrl":"10.1016/j.gexplo.2025.107954","url":null,"abstract":"<div><div>Pyrite, a prevalent mineral in gold deposits, records valuable information about fluid evolution and physicochemical conditions through its textures and composition. The Xiaoyingpan Au deposit in the North China Craton, characterized by multistage mineralization and deformation, provides an ideal setting to investigate these processes. This study integrates electron back-scattered diffraction (EBSD), trace element analysis, and S isotopes to decipher the paragenesis of three pyrite generations (Py1, Py2, Py3) and their implications for fluid evolution and gold endowment at Xiaoyingpan. Petrographic and EBSD results reveal that euhedral Py1 underwent plastic deformation and was subsequently altered to porous and inclusion-rich Py2 via deformation-assisted coupled dissolution-reprecipitation (CDR) reactions. Foam-like Py3 aggregates formed by deformation-induced dynamic recrystallization of Py1. Trace element compositions demonstrate contrasting behaviors during CDR and deformation: lattice-bound elements (Co, Ni) remained immobile, while inclusion-hosted elements (Au, Ag, Te, Cu, Pb) were extensively remobilized and enriched in Py2b domains, highlighting the critical role of deformation microstructures in controlling element redistribution. Consistent S isotope values across all pyrite types suggest a homogeneous S source, with later fluids primarily remobilizing pre-existing metals. We propose a multi-fluid model wherein a metal-rich fluid precipitated Py1 with tellurides and native gold, establishing the primary mineralization. Subsequent reactive and metal-poor fluids drove the dissolution-reprecipitation (forming Py2) and recrystallization (forming Py3) of Py1, respectively, modifying textures and locally upgrading gold grades without introducing significant new metals. This study highlights the importance of EBSD and trace element analyses to decipher formation mechanisms of complex textures in pyrite, which can be used to reveal mineralization and overprinting events in Au deposits.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"282 ","pages":"Article 107954"},"PeriodicalIF":3.3,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extreme H isotope fractionation of phyllosilicates from the Kiggavik Uranium deposits","authors":"Ian Burron ,&nbsp;Mostafa Fayek ,&nbsp;Julie Brown ,&nbsp;Alfredo Camacho","doi":"10.1016/j.gexplo.2025.107945","DOIUrl":"10.1016/j.gexplo.2025.107945","url":null,"abstract":"<div><div>The Kiggavik Uranium (U) Project in Nunavut, Canada hosts U deposits for which both unconformity-related and metasomatic‑iron-alkali-calcic genetic models have been proposed. We propose a five-phase genetic model consisting of: (1) albitization; (2) hematization and illitization; (3) bleaching and primary (U1) mineralization; (4) ∼1450 Ma to 274 Ma overprinting events linked to distant tectonic and igneous events, and: (5) geologically recent (∼471 Ka to 36 Ka) overprinting linked to subglacial meteoric fluids.</div><div>M2 muscovite formed during albitization of granitic rocks and is Ar-Ar dated to ∼1820–1830 Ma, which is consistent with igneous and seismic activity and albitite-hosted U mineralization in the region. M2 muscovite has δ²H values as high as +129 ‰. This high value is unprecedented in terrestrial minerals. M2 is in equilibrium with isotopically heavy (δ¹⁸O and δ²H values of +10.4 ± 2.1 ‰ and + 130 ± 31 ‰, respectively) fluids proposed to have been produced through multiple cycles of seismically-induced fluid boiling, phase separation, and condensation.</div><div>Multiple generations of illite, formed through retrograde metamorphic (Il1) and subsequent hydrothermal (Il2-Il5) processes, are present. Il3 and Il5 are isotopically consistent with precipitation from basinal fluids and with subsequent overprinting by meteoric fluids, while Il4 is isotopically consistent with highly fractionated, boiled fluids. Il3-Il5 illites yield post U1 Ar-Ar dates, reflecting overprinting events.</div><div>Highly fractionated fluids are strongly linked to albitization and an early albitite-style U mineralization event. Both highly fractionated and basinal fluids may have been involved in U1 mineralization. Basinal and meteoric fluids are strongly linked to post-depositional alteration events.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"282 ","pages":"Article 107945"},"PeriodicalIF":3.3,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Triassic post-collisional porphyry systems in the eastern Kunlun Orogen, Northern Tibet: Insights from the Wulanwuzhu'er CuAg mineralization","authors":"Zhongyuan Ma ,&nbsp;Jinyang Zhang ,&nbsp;Yong Zhang ,&nbsp;Jianxun Yuan ,&nbsp;Jiaxing Chai ,&nbsp;Lanxin Zhang","doi":"10.1016/j.gexplo.2025.107943","DOIUrl":"10.1016/j.gexplo.2025.107943","url":null,"abstract":"<div><div>Intermediate-sulfidation epithermal deposits are known to be associated with porphyry Cu and high-sulfidation epithermal deposits but also have recently been reviewed to be related to low-sulfidation epithermal deposits in back arcs or post-collisional porphyry Mo deposits. In this study, the newfound low- to intermediate-sulfidation epithermal Ag<img>Pb<img>Zn mineralization is shown to be linked with the nearby Wulanwuzhu'er porphyry Cu deposit in the post-collisional setting of the eastern Kunlun Orogen based on field relationships, alteration and mineralization, zircon and rutile LA-ICP-MS U<img>Pb dating, and <em>in situ</em> sulfide trace elements and sulfur isotopes. Late Triassic porphyries intruded into deformed Devonian monzogranites along the fault zones were involved in the Wulanwuzhu'er Cu<img>Ag mineralization. The Ag<img>Pb<img>Zn mineralization includes pyrite, chalcopyrite, pyrrhotite, sphalerite, galena, and argentite disseminated or in veins with kaolinization, sericitization, and chloritization. The Wulanwuzhu'er Cu deposit hosts veinlet-disseminated pyrite and chalcopyrite associated with potassic and sericitic alteration. Magmatic zircon in the Cu mineralized porphyry and magmatic hydrothermal rutile in Ag mineralized Devonian monzogranites yield similar LA-ICP-MS U<img>Pb ages of 213.2 ± 1.8 Ma and 211.7 ± 8.4 Ma, respectively. <em>In situ</em> trace elements and sulfur isotopes for pyrrhotite, six types of pyrite, and two types of chalcopyrite and sphalerite suggest that fluids for the Cu deposit ascended to shallow fault zones and underwent boiling to form the Ag mineralization. Therefore, other porphyry Cu, porphyry Mo, skarn Cu, and low- to intermediate-sulfidation epithermal Ag polymetallic deposits pertinent to Late Triassic post-collisional porphyries in the eastern Kunlun Orogen warrant further research and exploration for relevant styles of mineralization.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"282 ","pages":"Article 107943"},"PeriodicalIF":3.3,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145645621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Controls on heavy metal variability in a coastal mountainous river: Impacts of tides, typhoons, and anthropogenic activities","authors":"Yalong Li ,&nbsp;Ni Su ,&nbsp;Yun Zhao ,&nbsp;Ergang Lian ,&nbsp;Chao Li ,&nbsp;Juan Xu ,&nbsp;Ping Yin ,&nbsp;Shouye Yang","doi":"10.1016/j.gexplo.2025.107944","DOIUrl":"10.1016/j.gexplo.2025.107944","url":null,"abstract":"<div><div>Understanding the ecological risks of heavy metals is critical for effective environmental management. Yet, the combined influence of tidal processes and tropical storms on heavy-metal dynamics in rivers remains poorly understood. This study examines the variations of heavy metals in sediments from a typical mountainous river in Southeast China, aiming to assess the combined influence of tides and typhoons on metal enrichment and ecological risks. The results show that from 2016 to 2019, there were no significant temporal changes in the ecological risks of heavy metals. Nevertheless, a distinct spatial pattern was observed, with higher levels in the tidal reach than in the non-tidal reach. This spatial variation is due to changes in sediment composition, such as shifts in source areas and grain size, which are driven by tidal processes. The clay fraction had significantly higher concentrations of heavy metals, enrichment, and ecological risks because metals are preferentially adsorbed onto fine-grained particles. Under normal conditions, tidal activity and anthropogenic inputs mainly affect the distribution of heavy metals. However, during typhoons, sediment mobilization intensifies, leading to a 2–4-fold increase in heavy metal concentrations and a higher risk of environmental contamination. The results of this study suggest that effective management of heavy-metal contamination in dynamic river systems requires a holistic approach that considers sediment composition, hydrodynamic conditions, and anthropogenic activities.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"282 ","pages":"Article 107944"},"PeriodicalIF":3.3,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sulfide geochemistry and gold occurrence in the Yu'erya deposit, Eastern Hebei, China: Implications for mineralization and metallurgy","authors":"Liangjie Cui ,&nbsp;Qihai Shu ,&nbsp;Yue He ,&nbsp;Di Zhao ,&nbsp;Fan Yu ,&nbsp;Litian Zhang ,&nbsp;Qingfei Wang ,&nbsp;Jun Deng","doi":"10.1016/j.gexplo.2025.107946","DOIUrl":"10.1016/j.gexplo.2025.107946","url":null,"abstract":"<div><div>The Yu'erya gold deposit is located in eastern Hebei along the northern margin of the North China Craton, which is one of the typical gold deposits associated with Mesozoic granitic intrusions in the region. A systematic characterization on the gold occurrence and sulfide geochemistry are critical for understanding the mineralization process and guiding recovery strategy. However, such information is still lacking for Yu'erya. In this study, the automated mineralogy mapping using TESCAN Integrated Mineral Analyzer (TIMA) and sulfide compositional determination using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) have been conducted to investigate the gold occurrence and the coupled substitution behavior of Au with other trace elements in pyrite. The results indicate that embedded features of visible gold can be classified as fracture-hosted gold, included gold, and intergranular gold, with fracture-hosted gold being the dominant type, accounting for 57.32 % of the total. Based on the spatial distribution, visible gold is further classified into free gold (spatially independent) and intergrown gold (associated with other minerals), with free gold being the predominant type (67.78 %). In terms of grain size, visible gold can be further divided into four categories: micro-grained gold (1–5 μm), fine-grained gold (5–10 μm), medium-grained gold (10–20 μm), and coarse-grained gold (20–50 μm). Their proportions in terms of area are 8.10 %, 36.45 %, 37.21 %, and 18.24 %, respectively, and by quantity, the corresponding proportions are 38.91 %, 43.52 %, 15.06 %, and 2.51 %. The invisible gold primarily occurs as solid solutions or mineral inclusions, with its content varying among different sulfide minerals. The average concentrations are 0.92 ppm in pyrite, 1.11 ppm in chalcopyrite, and 0.49 ppm in sphalerite. Notably, tetrahedrite exhibits the highest average value (4.17 ppm), occurring exclusively as solid solutions. The Au content shows strong positive correlations with chalcophile elements (Ag, Bi, Cu, Pb, Sb, and Te) in pyrite, strongly indicating that Au-Cu-Sb-Ag-Bi complexes are incorporated into the pyrite lattice through coupled substitution of Fe²⁺ ions or as micro-mineral inclusions. These findings provide key insights into gold mineralization mechanisms and offer essential mineralogical constraints for ore beneficiation and metallurgical processing.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"282 ","pages":"Article 107946"},"PeriodicalIF":3.3,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Material source and genesis analysis of lithium-rich claystone in Balun Mahai Salt Lake, Qaidam Basin","authors":"Fan Zhang ,&nbsp;Xiwei Qin ,&nbsp;Yuliang Ma ,&nbsp;Sha Yang ,&nbsp;Tong Pan ,&nbsp;Jianzhou Chen ,&nbsp;Chenglin Liu ,&nbsp;Chengwang Ding ,&nbsp;Ziwen Jiang ,&nbsp;Dong Zhang ,&nbsp;Qingkuan Li ,&nbsp;Genhou Wang ,&nbsp;Ning Feng ,&nbsp;Ruibo Liu ,&nbsp;Zhaopeng Ding ,&nbsp;Erfeng Ren","doi":"10.1016/j.gexplo.2025.107935","DOIUrl":"10.1016/j.gexplo.2025.107935","url":null,"abstract":"<div><div>The potential resources of the clay-type lithium ore in the Balun Mahai Salt Lake of the Qaidam Basin are considerable. However, systematic theoretical research on the metallogenic enrichment regularity of the clay-type lithium ore is still lacking. In this paper, the Quaternary clay layer in the Balun Mahai Basin is taken as the research object. By adopting the methods of rock geochemistry and isotope geochemistry, the sedimentary environment, material source, evolution process and lithium source of the lithium-rich clay layer are explored. The distribution pattern diagrams of rare earth elements indicate that the lithium - rich clay rocks in the Mahai Basin are enriched in light rare earth elements and depleted in heavy rare earth elements, presenting distinct fractionation within the rare earth element assemblage, and the materials of the source rock and the weathering conditions remain stable. The elemental indicators of the sedimentary environment and the isotope indicators of B, C, and O suggest that the sedimentary water body was in a non - marine brackish water environment with weak oxidation - weak reduction conditions, which was affected by a climate characterized by aridity and scarce precipitation. The sediment provenance discrimination diagrams and rare earth element distribution pattern diagrams suggest that the clay source rocks are primarily derived from the biotite adamellite, quartz diorite, gneissic granite of Little Seshten Mountain, adamellite of Qaidam Mountain in the South Qilian Mountains and the granitic gneisses in the Yuqia River region. Weathering indices such as Chemical Index of Alteration (CIA) and Index of Compositional Variability (ICV) indicate that the source rocks generated detrital materials under the influence of weak weathering processes. These detrital materials were then transported to the basin via rivers and, through sedimentation and diagenesis, gave rise to clay minerals. Subsequently, in an alkaline fluid environment, the potassium feldspar was transformed into illite. The isotopic characteristics of Li and B suggest that the lithium in the clay has two sources: lithium in the enriched brine and lithium in the detrital materials of the retained source rocks. Moreover, the amount of lithium adsorbed from the brine is higher than that of the structural lithium in the source rock detritus. Through a comprehensive analysis of the sedimentary environment, material sources, evolution process, and lithium sources of the lithium - rich clay, its genesis can be divided into multiple stages, including the weathering of parent rocks, material transportation, sedimentation, and diagenesis.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"281 ","pages":"Article 107935"},"PeriodicalIF":3.3,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Removal notice to “Ore-forming processes of the Chuankou tungsten ore field, South China: New insights into Maowan quartz veins scheelite generation and mineralization genesis” [GEXPLO 278(2025) 107864]","authors":"Or Aimon Brou Koffi Kablan ,&nbsp;Binhai Wang ,&nbsp;Yuzheng Shi ,&nbsp;Syed Yasir Ali Shah ,&nbsp;Baoyi Zhang","doi":"10.1016/j.gexplo.2025.107910","DOIUrl":"10.1016/j.gexplo.2025.107910","url":null,"abstract":"","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"281 ","pages":"Article 107910"},"PeriodicalIF":3.3,"publicationDate":"2025-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mineral weathering and water chemistry of pyrrhotite- and serpentine-bearing mine wastes under freeze-thaw cycles","authors":"Gary Schudel ,&nbsp;Bruno Bussière ,&nbsp;Joyce M. McBeth ,&nbsp;Benoît Plante","doi":"10.1016/j.gexplo.2025.107933","DOIUrl":"10.1016/j.gexplo.2025.107933","url":null,"abstract":"<div><div>The mineralogical composition of mine wastes is generally considered to be the most important determinant of mine water geochemistry. However, environmental factors can significantly modify the weathering behavior of these materials, and the failure to consider these factors in experimental work may yield biased results. This is a particularly important consideration for mines in arctic and sub-arctic regions, where environmental conditions are far from those of a typical laboratory. The present study focuses on evaluating the influence of ambient thermal conditions on the weathering of pyrrhotite- and serpentine-rich tailings. To this end, laboratory-scale leached columns were used to simulate weathering of tailings over 544 days either at room-temperature or under freeze-thaw cycles (−20 °C/+20.5 °C). Microbiological analyses performed as part of the initial material characterization were unable to detect microbial communities. Although this result was unexpected and unusual, we found that elemental sulfur, which is stable in the absence of sulfur-oxidizing bacteria, had accumulated in the weathered tailings, representing up to 89–92 % sulfur products from pyrrhotite oxidation. Thiosulfate and sulfate were important oxidation products in leachates under both thermal conditions; however, freeze-thaw cycling appeared to enhance the stability of thiosulfate. The dominance of elemental sulfur and thiosulfate, which are produced via non-acid-generating reactions, suggests that the hydrolysis of Fe³⁺ and Al³⁺ may have been comparatively important sources of acid generation. Serpentine dissolution was more extensive at room-temperature but likely provided little to no alkalinity under freeze-thaw conditions due to slower dissolution kinetics. Calcite and dolomite were the principal buffering phases despite their low abundance. The mobility of Zn seemed to not be limited in either test, whereas Fe and Ni were effectively sequestered via adsorption and/or coprecipitation with ferrihydrite and gibbsite. Under room-temperature conditions, depletion or passivation of the carbonate minerals gave rise to a new buffering regime controlled by gibbsite. Although this maintained the pH around 5.1, aqueous Fe and Ni concentrations spiked (max = 7.6 and 1.5 mM, respectively) as they were released or desorbed from the gibbsite. Leachate pH values remained slightly elevated in the freeze-thaw tests and had not yet stabilized by the end of the experiment; the sequestration of Fe and Ni was not disrupted.</div></div>","PeriodicalId":16336,"journal":{"name":"Journal of Geochemical Exploration","volume":"281 ","pages":"Article 107933"},"PeriodicalIF":3.3,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145617351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}